落葉の分解にともなう有機物組成の変化について

Abstract

A_o層の有機物組成の季節的な変化を調べた。分解にともなう組成の変化を明らかにするためにアカマツおよびヒメヤシャブシを用いてリターバッグで分解させた。そして, ブナ, アカマツ, ヒノキの3林分のLおよびF層を季節ごとに集めて分析した。1. 有機物組成の減少の速さはアカマツ, ヒメヤシャブシともに分解の速さに関係なく, 組成によって異なった。水溶性物質, エーテル・アルコール抽出物が最も速く減少し, ヘミセルローズ, セルローズがこれに次いで減少した。しかし粗蛋白質やリグニンは減少しにくく, 分解にともなって含有率が増加した。2. ブナ林では, L層の組成が季節の進行とともに徐々にF層の組成に近づいた。またアカマツ林では組成の変化は複雑で, 夏の初めに, 組成が増加し, その後はF層の組成に近づいた。ヒノキ林では明らかな季節変化はみられなかった。F層については, 有機物組成はどの林分でも明らかな季節による変化はみられなかった。A_o層の有機物組成の季節変化は各林分によって異なった型をしめし, これは各林分のリターの分解の進行と落葉量の季節的配分に対応するようである。

The report deals with the seasonal changes of the organic constituents of forest floors (A0 layer). In order to make clear the changes of organic constituents with the progress of decomposition, fresh litter of two tree species (Pinus densiflora and Alnus pendula) were put into nyron net, and set in the stand of Pinus densiflora. On the other hand, L and F layer of three different stands (Fagus crenata, Pinus densiflora and Chamaeacyparis obtusa) were collected and analyzed in every season. 1. The rate of diminution differed for each organic constituent. Regardless with tree species and the rate of decomposition, following results were obtained: water soluble fraction and ether-alcohol soluble fraction were decreased most easily in both tree species. Hemicellulose and cellulose were also decreased, but the rate of decrease were slower than the above two components. Crude protein and lignin were hard to decrease, and the contents were increased with decomposition. 2. In Beech stand the organic constituent of L layer gradually changed to that of F layer during the experimental period (Nov. 1969 to Nov. 1970). In Pine stand the organic constituent was somewhat complex. It changed to that of F layer during experimental period, but in early summer the progress of change was reversed. In Chamaecyparis obtusa stand there was no definit seasonal change. As for F layer, the organic constituents were nearly constant for every stand and season. The seasonal change of organic constituents of A0 layer showed different pattern for each stand. It would depend on the rate of decomposition of litter and the amount and the distribution of litter fall through a year.